Configuring Fabric Parameters - HP StorageWorks 2/64 - Core Switch Administrator's Manual

Configuring fabric parameters

You can configure the following fabric parameters using the Configure tab and Fabric subtab of the
Switch Admin module (as shown in
• BB Credit, which is the number of buffers available to attached devices for frame receipt. The default
BB Credit is 16. The range is 1 through 27.
• R_A_TOV, which is the resource allocation timeout value (in milliseconds). This variable works with the
E_D_TOV to determine switch actions when presented with an error condition. The default is 10000.
The possible range is 4000 through 120000.
• E_D_TOV, which is the error detect timeout value (in milliseconds). This timer is used to flag a potential
error condition when an expected response is not received within the set time. The valid range is
1000 through 5000.
• Datafield size, which is the largest possible datafield size (in bytes). The valid range is 256 through
2112.
• Switch PID Format, which selects a switch PID format from one of the following:
• Format 1 (0-base, 256 encoding)
• Format 2 (16-base, 256 encoding)
• Sequence Level Switching: Check this box to enable frames of the same sequence from a particular
group to be transmitted together. When this option is not selected, frames are transmitted interleaved
among multiple sequences. Under normal circumstances, sequence-level switching should be disabled
for better performance. However, some host adapters have issues when receiving interleaved frames
among multiple sequences.
• Disable Device Probing: Set this mode only if the switch N_Port discovery process (PLOGI, PRLI,
INQUIRY) causes an attached device to fail. When set, devices that do not register with the Name
Server are not present in the Name Server database.
• Per-Frame Routing Priority: Choose to select or deselect per-frame routing priority. When enabled, the
virtual channel ID is used in conjunction with a frame header to form the final virtual channel ID.
• Suppress Class F Traffic: Applies only if VC-encoded address mode is also set. When checked,
translative addressing (which allows private devices to communicate with public devices) is disabled.
• Insistent Domain ID Mode: Set this mode to make the current domain ID insistent across reboots,
power cycles, and failovers. This mode is required fabric wide to transmit FICON data.
Figure 9):
Fabric OS 5.x Advanced Web Tools administrator guide 41